JPH03186604A - Friction type clamp device - Google Patents

Abstract

PURPOSE:To allow processing with less accuracy and to enhance the reliability by providing a sleeve and radially movable pistons in the bore section of an outer cylinder in an oil-tight manner so that a rod in the bore section of the sleeve is connected and disconnected to and from the outer cylinder through the intermediary of the pistons and the sleeve in response to the presence of hydraulic pressure. CONSTITUTION:An oil passage 12 is formed in an outer cylinder 4 arranged at the outer periphery of a rod 2, which passage 12 is opened to the inner peripheral part of the outer cylinder 4, and a sleeve 6 having a flange part 18 at its inner bore part 16 and formed therein axial three-stage piston holes 8 which are four in number being extended radially, is fitted in the outer cylinder 4. Seal members 20, 21 hold the outer cylinder 4 and the sleeve 6 in an oil-tight manner. Pistons 10 are fitted in the piston holes 8 so as to be movable in the radial direction, and accordingly, they can make into contact with the rod 2 with a large friction force. Further, an oil passage 12 is communicated with the piston holes 8 through an annular groove part 14. Accordingly, the less accurate processing of the clearance between the rod 2 and the sleeve 6 can be allowed, and it is possible to enhance the reliability even under variation in temperature.

Description

[Detailed description of the invention] (b) Industrial application field The present invention relates to a friction type clamp device.

(B) Prior art As a friction type clamp device, there is one in which a rod 30 and a sleeve 40 with a flange are fastened or released by hydraulic pressure, as shown in FIG. Hydraulic pressure is supplied to an oil chamber 60 formed between the sleeve 40 and an outer cylinder 50 fitted therein through an oil passage 70 communicating therewith. That is, for example, the inner diameter of the sleeve 40 is fitted to the outer diameter of the rod 30 so that they can move in the axial direction when no external force is applied, and when it is necessary to fasten the two, oil is removed from the outer diameter of the sleeve 40. By applying pressure, the sleeve 40 is elastically deformed in the radial direction, and the two are fastened together by frictional force.

Note that an oil chamber 6 is provided above and below between the sleeve 40 and the outer cylinder 50.
A seal 80 is provided to keep the 0 oil tight.

(c) Problems to be Solved by the Invention However, when the rod 30 is directly clamped by the sleeve 40 as described above, in order to function sufficiently as a friction type clamp device, it is necessary to The accuracy of the gap is important. If the air temperature or the temperature of the hydraulic oil supplied to the oil chamber 60 changes, this gap will change due to heat, tension, or thermal contraction. The problem was that it didn't. Furthermore, when the rod 30 and the sleeve 40 are in a fastened state and a relative force is applied between them as indicated by arrows in opposite directions in FIG. and are pressed against each other, most of the load is applied to the vicinity of the brim of the sleeve 40, indicated by a in the figure. In order to withstand this load, it is necessary to increase the wall thickness of the sleeve 40, and accordingly, there is a problem in that it is necessary to increase the hydraulic pressure for pressing the sleeve 40 against the rod 30. .

The present invention aims to solve such problems.

(d) Means for Solving the Problems The present invention provides a sleeve having a piston hole that penetrates between the inner and outer diameter portions in the radial direction between the rod and the outer cylinder, and a piston that is movably fitted into the piston hole. By combining these two methods, the above problems can be solved. That is, the friction type clamp device of the present invention is a friction type clamp device that fastens or releases a rod (2) and an outer cylinder (4) provided on the outer periphery of the rod (2), and the inner diameter of the outer cylinder (4) is The sleeve (6) has a piston hole (8) that is oil-tightly attached to the piston hole and penetrates between the inner and outer diameter portions in the radial direction, and a piston (10) that is oil-tightly fitted into the piston hole (8). The outer cylinder (4) is
It has an oil passage (12) that opens toward the inner circumference and communicates with the piston hole (8), and the rod (2) provided on the inner circumference of the sleeve (6) is connected to the piston (10).
When the oil pressure from the oil passage (12) is not acting on the piston (10), it can move in the axial direction, and the oil passage (12)
When hydraulic pressure from the piston (10) and the sleeve (6) are applied, the piston (10) and the sleeve (6) are connected to each other.

In addition, if a plurality of pistons (10) are provided at equal intervals on the circumference with the rod (2) in between, the rod (2)
can be tightened with uniform force from the radial direction. Furthermore, if a plurality of pistons (10) are provided in the axial direction by increasing the axial dimensions of the outer cylinder (4) and the sleeve (6), the radial dimension of the outer cylinder (4) can be increased. The clamping force can be increased without having to do so or increase the hydraulic pressure supplied to the piston (10).

Note that the symbols in parentheses indicate corresponding members in the embodiments described later.

(e) Put hydraulic oil into the piston hole of the sleeve from the oil passage of the working outer cylinder,
When pressure is applied, the piston within the piston hole is forced radially toward the rod, thereby clamping the rod and the barrel.

(f) Example FIG. 1 shows a longitudinal section of an example of the present invention, and FIG.
A cross section taken along the line ■-■ in the figure is shown.

The outer tube 4 provided on the outer circumference of the cylindrical rod 2 is provided with an oil passage 12 that opens to the inner circumference.
6 has a collar portion 18, and has four stages in the radial direction as shown in FIG. 2, and three stages in the axial direction as shown in FIG.
A sleeve 6 having two piston holes 8 is fitted together.

Seal members 20 and 21 are attached to the upper and lower portions of the inner diameter portion 16 of the outer cylinder 4 to maintain oil tightness with the sleeve 6. A total of 12 pistons 10, the same number as the piston holes 8, are fitted into the piston holes 8 of the sleeve 6 so as to be movable in the radial direction. The inner end surface 28 of the piston 10 is cut out in the shape of a partial cylindrical hole with an arc equal to the radius of the rod 2, so that when it is pressed against the rod 2, as large a frictional force as possible can be obtained. A seal member 22 for sealing the piston 10 is provided in the piston hole 8. A part of the outer diameter of the sleeve 6 which is fitted into the inner diameter part 16 of the outer cylinder 4 is cut out in a ring shape to form an annular groove part 14 together with the inner diameter part 16 of the outer cylinder 4. That is, the oil passage 12 communicates with the piston hole 8 via the annular groove 14. The rod 2 is inserted into the inner diameter portion 24 of the sleeve 6 with a relatively large gap so as to be movable in the axial direction when no hydraulic pressure is applied to the piston 10 from the oil passage 12. Seal members 26 and 27 are provided above and below the inner diameter portion 24 of the sleeve 6 in the axial direction to maintain oil tightness with the rod 2.

Next, the operation of this embodiment will be explained. When oil pressure is not acting on the piston hole 8 from the oil passage 12, no force is acting between the outer diameter of the rod 6 and the rod side end surface 28 of the piston 10, so the rod 6 moves in the axial direction. can be done.

That is, the friction clamping device is in a released state.

When hydraulic pressure is applied to the piston hole 8 through the oil passage 12 from this state, a force in the axial direction is applied to the piston 10, and its end surface 28 is pressed against the outer diameter portion of the rod 2. As a result, the rod 2 and the piston 10 come into metal contact. This frictional force causes the rod 2 to move toward the piston 10.
and is clamped to the outer cylinder 4 via the sleeve 6. That is, the friction type clamp device is in a fastened state.

(G) As described in detail, according to the present invention, a sleeve in which a radially movable piston is fitted is provided between the rod and the outer cylinder, and hydraulic pressure is applied to the piston. Since the rod is clamped, the gap between the rod and the sleeve does not require strict precision (this means that even under operating conditions such as temperature fluctuations, the reliability of the operation of the 1m! type clamping device can be improved). In addition, since the magnitude of the hydraulic pressure directly pushes the piston, there is no need for an unnecessarily large hydraulic pressure.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing the clamped state of the embodiment of the present invention, Fig. 2 is a transverse sectional view taken along the cross-sectional line ■-■ in Fig. 1, and Fig. 3 is a longitudinal sectional view of a conventional friction type clamp device. It is a front view. 2... Rod, 4... Outer cylinder, 6... Sleeve, 8... Piston hole, 10... Piston,
12... Oil passage, 14... Annular groove.

Claims (1)

[Claims] 1. In a friction type clamp device for fastening or releasing a rod (2) and an outer cylinder (4) provided on the outer periphery thereof, an oil-tight seal is provided on the inner diameter of the outer cylinder (4). It has a sleeve (6) that is attached and has a piston hole (8) that penetrates radially between the inner and outer diameter parts, and a piston (10) that is fitted in the piston hole (8) in an oil-tight manner, and the above-mentioned Outer cylinder (4)
has an oil passage (12) that opens toward the inner circumference and communicates with the piston hole (8), and the rod (2) provided on the inner circumference of the sleeve (6) is connected to the piston (1).
When the oil pressure from the oil passage (12) is not acting on the piston (10), it is movable in the axial direction;
If hydraulic pressure from 2) is applied, the piston (10)
and a friction type clamp device configured to be connected to the outer tube (4) via the sleeve (6). 2. A plurality of pistons (10) are provided at equal intervals on the circumference with the rod (2) in between, and the oil passage (12) is an annular groove that communicates with each piston hole (8). (
14) The friction type clamp device according to claim 1, which has the following features. 3. A plurality of pistons (10) are provided in the axial direction, and the oil passage (12) is connected to each piston hole (8).
3. The friction clamp device according to claim 1, wherein the friction clamp device is configured to communicate with the friction clamp device.